When she took a job as an assistant professor of engineering and computer-aided drawing two years ago at Pierce College, a two-year college in Los Angeles, she took the pay cut along with it. Her salary dropped to $60,000 from $90,000, the Chronicle reported.

Cheung said she does not regret her decision; she enjoys more flexibility while raising her daughter. She teaches five classes a semester.

Stagnant faculty salaries for Cheung and teaching professionals across the U.S. belie the common belief that professors' incomes are driving increased costs of higher education, the American Association of University Professors (AAUP) reported in a study released on Monday.

In a report called, "A Very Slow Recovery: The Annual Report on the Economic Status of the Profession, 2011–12," the AAUP says the overall average salary for full-time faculty members, on average, rose 1.8 percent in the 2011 to 2012 academic year.

In the past decade at public two-year colleges, such as the one where Cheung teaches, published tuition and fees, excluding scholarship aid and adjusted for inflation, have increased by 44.8 percent. Faculty salaries, meanwhile, have decreased by 2.5 percent, according to the report.

Over the past decade at public four-year colleges and universities, tuition and fees have increased by 72 percent, the association said.

Colleges and universities are also relying less on tenured faculty to teach classes and more on part-time faculty who may be paid as little as $2,000 to teach a course, Thornton said. Over 60 percent of instructional staff in 2009 were either part-time faculty or graduate students.

The average salary is $82,556 for professors, many of whom have invested years and hundreds of thousands of dollars in their own education.

The gap between the pay of college presidents and professors widens meanwhile, said the AAUP, which has 47,000 members at colleges and universities in the U.S. Between the 2006-2007 academic year and the 2010-2011 year, median presidential salaries increased 9.8 percent when adjusted for inflation.

With a three percent rate of inflation, faculty salaries actually fell by an average of 1.2 percent, the group said. The average salary increase for faculty members who remained employed at the same institution, 2.9 percent, barely kept pace with inflation, the group said.

Saranna Thornton, professor of economics and department chair at Hampden-Sydney College in Virginia and chair of the AAUP's Committee on the Economic Status of the Profession, was the primary author of this year's report. She said data for the last ten academic years, 2001-2002 to 2011-2012, shows that, adjusted for inflation, the research "demonstrates unequivocally that faculty salaries are not driving up the costs of higher education."

John Curtis, director of research and public policy with the American Association of University Professors, said there are frequent assertions from legislators and others that say otherwise.

When a parent asked Vice President Joseph Biden in January why college costs continue to rise, one of the reasons he pointed to was faculty pay, The Chronicle of Higher Education reported.

"Salaries for college professors have escalated significantly," Biden said during a town hall in Pennsylvania. "They should be good, but they have escalated significantly."

Curtis said the data in this year's report demonstrate that is not true.

"Over the course of a number of these annual reports, we've been making the case that the real issue is priorities," Curtis said. "Full-time faculty salaries have been stagnant, and an increasing proportion of instruction is being shifted to part-time faculty members who are poorly paid, not provided with benefits, and not provided with the support they need to do the jobs they are capable of."

As a result, he said, the proportion of higher-education spending that goes to instruction has been declining.

So what's driving tuition hikes?

Tuition prices have been rising, in part, because state funding is providing a smaller proportion of revenues, and institutions have shifted more of the burden to students and their families, Curtis said. At the same time, financial aid awards have not kept pace, and have been converted primarily into loans rather than grants, thereby increasing the student debt burden.

The rise in tuition prices has coincided with rapid growth in part-time faculty appointments that can pay low wages and usually do not include benefits, the group reported.

Sara Hebel, senior editor at the Chronicle of Higher Education, said the overall theme of the group's report is that faculty pay, like higher education as a whole, is facing a slow recovery.

"It's been a struggle for many institutions, and more so for the public ones," she said.

"Again, it's about priorities," Curtis said. "Within institutions, the primary focus must return to funding the academic mission by supporting all of the faculty members who teach the students and do the research that benefits society. As a nation, we need to make a renewed commitment to match the acknowledged importance of higher education with sufficient funding to keep it affordable."

Over 90 percent of the CEOs of large corporations are college graduates who learned skills in business and engineering, but also in English composition, foreign languages and mathematics, Thornton said.

"So, I would argue that the real 'job-creators' are the college professors who taught the CEOs," Thornton said. "With an average pay of $82,556 for full-time faculty, "that professor doesn't even make it into the top 20 percent, much less the top 1 percent."